Bidirectional single-fiber filterless optical networks: modeling and experimental assessment

This paper proposes, designs, and validates a filterless metro network employing bidirectional transmission over a single fiber. Transmission impairments, dominated by cross talk, are specifically estimated leveraging on what we believe to be novel closed-form expressions to determine optical reach, launch power, and number of supported cascaded nodes. Results show that extremely good transmission performance can be achieved and further improved when misalignment in spectrum allocation is configured among the two counter-propagating directions. This confirms that filterless metro networks employing bidirectional transmission over a single fiber represent an extremely attractive solution, particularly in the case of scarce fiber availability and when regulatory aspects impose a rent for any occupied fiber infrastructure.